Hybrid experimental and computational approach for rate dependent mechanical properties using indentation techniques

This paper introduces a hybrid test methodology, based on dynamic indentation, to determine the high strain rate properties of materials. A conical indentation test setup, with real time measurement of load and indent depth, is developed for this purpose. Tests are conducted to obtain the load displacement (P-h) curves at different loading rates. Non-linear dynamic finite element analysis (FEA), using an iterative inverse solution technique, is used to convert the experimental data into stress-strain curves at different strain rates. The inverse solution technique involves varying the stress-strain curves until the load-displacement curves obtained from simulation matches the experimentally measured data. Results indicate that the uni-axial dynamic characterization tests under-predict the material properties of the specimen, when compared to the indentation tests. This is important for the characterization of materials that experience localized plasticity; eg. Structures subjected to drop and impact.